Effect of Anti-Inflammatory Compounds on β-Irradiation Induced Radiodermatitis

The effect of several anti-inflammatory agents given <i>per os</i>, intraperitoneally, or topically to alleviate acute radiodermatitis in guinea pig skin following 3,000 or 4,000 rep β-irradiation was studied. Up to the 21st day post-irradiation, there was pronounced suppression of the acute inflammatory response observed with chloroquine diphosphate, or meclofenamic acid (Cl-583). Chloroquine diphosphate given systemically was most potent among the single drugs tested. Qualitatively, combinations of the drugs given <i>per os</i> were somewhat more effective in suppression of the second erythema and late skin reactions. Topical application of 50% DMSO or of anti-inflammatory drugs dissolved in this solvent resulted in increased inflammatory reactions. Triamcinolone acetonide appeared to be the only active compound when applied topically. The effective anti-inflammatory agents decreased the frequency but did not prevent the onset of ulcers. Ulceration was delayed by about 10 days in the drug-treated animals (as compared with its appearance by the 20th day in controls) and the ulcerated area was smaller and healed more rapidly.